protected override void OnPreviewMouseLeftButtonDown(MouseButtonEventArgs e)
{
base.OnPreviewMouseLeftButtonDown(e); // call the handler of the base first
m_IsDragInProgress = false;
m_InitialCursorLocation = e.GetPosition(this); // Cache the mouse cursor location
//check if the mouse was clicked on the ScrollBar, in which case let the ScrollBar remain its control.
if (null != GetParentOfType <ScrollBar>(e.OriginalSource as DependencyObject))
{
return;
}
// Walk up the visual tree from the element that was clicked,
// looking for an element that is a direct child of the Canvas
DraggedElement = FindCanvasChild(e.Source as DependencyObject);
if (m_DraggedElement == null)
{
return;
}
// Custom - select dragged element
if (DraggedElement.GetType() == typeof(Rectangle) || DraggedElement.GetType() == typeof(Ellipse))
{
Shape element = (Shape)DraggedElement;
MainWindow window = GetMainWindow();
window.SelectItem(element);
}
m_ModificationDirection = ResolveOffset(Canvas.GetLeft(m_DraggedElement), Canvas.GetRight(m_DraggedElement), Canvas.GetTop(m_DraggedElement), Canvas.GetBottom(m_DraggedElement));
// Set the Handled flag so that a control being dragged
// does not react to the mouse input
e.Handled = true;
if (m_ModificationDirection == ModificationDirection.None)
{
DraggedElement = null;
return;
}
BringToFront(m_DraggedElement as UIElement);
m_IsDragInProgress = true;
}
